Understanding the cash back or low interest calculator
Car dealers often force a choice: take a cash rebate now, or take special low-rate financing you can't have both. The right answer depends on the loan size and term. A rebate lowers the amount financed immediately, while low-rate financing reduces interest over time; which wins isn't obvious without running both.
As a rule, cash back tends to win on shorter loans and smaller balances, where there's little interest for a low rate to save. Low-rate financing tends to win on longer terms, where the interest savings compound. This calculator computes the total cost of each path so the cheaper one is unambiguous and remember the rebate is also useful if you can invest or save it instead.
Results are estimates for education only and are not financial advice.